Read-only recording medium and reproducing method thereof

ABSTRACT

A read-only recording medium and a reproducing method thereof, are discussed. According to an embodiment, the read-only recording medium includes a plurality of data units recorded on the read-only recording medium, each data unit connected by a linking data unit having a predetermined size, wherein the linking data unit is identified by an identifier.

This application is a divisional of U.S. patent application Ser. No.10/893,033, allowed Jan. 25, 2007, which is a divisional of U.S. patentapplication Ser. No. 10/092,703 filed Mar. 5, 2005, which claims thepriority benefit of Korean Patent Application No. 2001-12149, filed onMar. 9, 2001. The entire contents of each of these applications arehereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a read-only recording medium and areproducing method thereof. A read-only recording medium in accordancewith the present invention ensures reproduction compatibility with arewritable recording medium in which real-time data such asmoving-picture and audio data is recorded with substantialdiscontinuity.

2. Description of the Related Art

A disk of large storage capacity, called ‘DVD’, which has been developedto store high-quality moving pictures for longer time than a compactdisk (generically called ‘CD’), is expected to be widely used. The DVDhas three types, ‘read-only’ such as a DVD-ROM, ‘write-once’ such as aDVD-R, and ‘rewritable’ such as DVD-RAM or DVD-RW.

The read-only type, namely, the DVD-ROM which is being widely used atpresent is a high-density recording medium and is 4.7 Gbytes in storagecapacity. This capacity is about eight times as large as a conventionalCD. The DVD-ROM has two recording areas for user data and managementinformation. A real-time data, such as high-quality moving-picture dataor audio data, has been recorded seamlessly in the data recording area,and management information such as navigation data for reproductioncontrol of recorded real-time data has been recorded in the managementinformation recording area.

FIG. 1 is a hierarchical structure of real-time data recorded in thedata recording area of a DVD-ROM. The recorded real-time data shall beconstructed with at least one video object (VOB) which is a datacollection corresponding to a video title or chapter. The VOB shallconsist of a plurality of video object units (VOBUs). Each VOBU shallconsist of two ECC blocks each of which shall consist of 16 sectors.Because the size of a sector is 2048 Bytes the ECC block is about 32Kbytes in size.

A disk device, such as a DVD player or a DVD drive, capable ofreproducing a DVD-ROM reads the management information for recorded datafrom the management information recording area first, and thenreproduces the real-time data structured as FIG. 1 from the datarecording area with reference to the read management information.Because the real-time data has been recorded continuously, a seamlessreproduction can be accomplished only if the real-time data is outputtedin the order of reproduction without any special data manipulation.

In the meantime, the concrete standard for a rewritable DVD, such as aDVD-RAM or a DVD-RW, is under development. Such a rewritable DVD has thesame storage capacity of 4.7 Gbytes as the read-only DVD-ROM.

Thus, if such a rewritable DVD is commercially and commonly used as adata storage means, a user can record desired digital televisionbroadcast programs for a long time or copy real-time data stored in aDVD-ROM onto a DVD-RAM or a DVD-RW through a disk device like a DVDrecorder.

As explained above, the real-time data has been stored seamlessly in aDVD-ROM. However, the real-time data is recorded discontinuously in therewritable DVD because an area for header information or linking loss isallocated intermittently among real-time data.

FIG. 2 shows a data structure recorded discontinuously in a rewritableDVD-RW. As shown in FIG. 2, RMA (Recording Management Area) except RMALead-in is constructed with 5 RMA segments. Each RMA segment consists of28 RMD (Recording Management Data) sets. Each RMD set consists of aplurality of 32-Kbyte RMD blocks each of which is constructed with 15data fields and a linking loss area of 2 Kbytes in which valid real-timedata is not to be written. Because a linking loss area is inserted atthe head of every RMD block the data recorded in the DVD-RW is indiscontinuous recording state.

Usually a linking loss area is provided for sufficient buffering forfacilitating fully random write or overwrite.

Because of the linking loss area or the header information area in whichvalid data shall not be written, the substantial storage capacity of aDVD-RAM or DVD-RW is correspondingly reduced from the nominal capacityof 4.7 Gbytes. Thus, the entire data stored in a DVD-ROM can not becopied onto a DVD-RAM or a DVD-RW.

When a DVD-ROM is placed in a disk device, such as a DVD player or adisk drive, the disk device can reproduce real-time data stored in aDVD-ROM seamlessly by simply outputting data read from a DVD-ROM inreading order without any special manipulation. However, if a rewritableDVD-RW or DVD-RAM which data has been discontinuously recorded onto isplaced in, a disk device must conduct a special operation to accomplishseamless reproduction, namely, it temporarily stores all data read fromthe rewritable disk, deletes data read from the header information orthe linking loss area, and outputs real data before and behind theheader information or the linking loss area. Accordingly, a disk devicemust be equipped with different reproduction algorithms which areselectively used based on the type of a placed disk.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a read-onlyrecording medium in which real-time data such as moving-picture or audiodata has been stored discontinuously by inserting waste areas atintervals among the stored real-time data in order to ensurereproduction compatibility with a rewritable recording medium such as aDVD-RAM or a DVD-RW and to make the storage capacity of a read-onlyrecording medium equal to that of a rewritable recording medium.

It is another object of the present invention to provide a ROM mediumcompatible with a future RAM medium in data reproduction.

It is another object to provide a method of seamlessly reproducing datastored in a read-only recording medium where waste areas are allocatedat intervals among the stored real-time data in accordance with thepresent invention.

A read-only recording medium in accordance with an aspect of the presentinvention comprises a data recording area in which real data is stored;and a plurality of waste areas allocated at intervals in the datarecording area.

A method of reproducing data stored in a read-only recording medium inaccordance with another aspect of the present invention comprises thesteps of: reproducing data from the read-only recording medium; skippingif a waste area is encountered or removing invalid data reproduced fromthe waste area wherein each waste area has been inserted periodically inthe read-only recording medium; and outputting the reproduced databefore and behind each waste area in succession.

According to another aspect, the present invention provides a read-onlyrecording medium, comprising: a plurality of data units recorded on theread-only recording medium, each data unit connected by a linking dataunit having a predetermined size, wherein the linking data unit isidentified by an identifier.

According to another aspect, the present invention provides a read-onlyrecording medium, comprising: a plurality of data units recorded on theread-only recording medium, each data unit connected by a linking dataunit having a predetermined size, wherein the linking data unit isidentified by a position of the linking data unit inserted in a tail orhead of the data unit.

According to another aspect, the present invention provides a read-onlyrecording medium, comprising: a plurality of data units recorded on theread-only recording medium, each data unit recorded discontinuously by afirst data area, wherein the each data unit includes real data, and thefirst data area includes an invalid data and an identifier to identifythat the area is the first data area.

According to another aspect, the present invention provides a method ofreproducing data stored in a read-only recording medium, comprising:checking whether or not a current position is a linking data area basedon an identifier to identify the linking data area, the linking dataarea preceded and followed by a real data area; and removing a uselessdata in the linking data area and outputting continuously the real datain the real data area before and behind the linking data area, when theidentifier is detected.

According to another aspect, the present invention provides a method ofreproducing data stored in a read-only recording medium, comprising:checking whether or not a current position is an invalid data area basedon a position of the invalid data area inserted in a tail or head of areal data area; and removing the invalid data and outputtingcontinuously the real data before and behind the invalid data, when thecurrent position is the tail or head of the real data area.

The present invention may be embodied in other specific forms withoutdeparting from the sprit or essential characteristics thereof. Thepresent embodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the followingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the present invention, illustrate the preferredembodiments of the invention, and together with the description, serveto explain the principles of the present invention, and wherein:

FIG. 1 is a conventional hierarchical structure of real-time data storedin a DVD-ROM;

FIG. 2 shows a data structure recorded discontinuously in a rewritableDVD-RW;

FIG. 3 is an illustrative structure of data constructed onto a read-onlyrecording medium manufactured in accordance with the present invention;

FIG. 4 is a simplified block diagram of a disk device which areproducing method for a read-only recording medium according to thepresent invention is embedded in; and

FIG. 5 is a flow chart of an embodiment of a method reproducing areal-only recording medium manufactured in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFFERRED EMBODIMENTS

In order that the invention may be fully understood, preferredembodiments thereof will now be described with reference to theaccompanying drawings.

FIG. 3 is an illustrative structure of data constructed onto a read-onlyrecording medium in accordance with an embodiment of the presentinvention. The same as the data structure of FIG. 1, the real-time dataof FIG. 3 is constructed with at least one VOB which is a datacollection corresponding to a video title or chapter, the VOB consistsof a plurality of VOBUs, and the VOBU consists of two ECC blocks each ofwhich consists of 16 sectors. However, a waste area of 2 Kbytes isallocated every 16 sectors, namely, one ECC block in the embodiment ofFIG. 3 in accordance with the present invention.

In a preferred embodiment, even though a waste block is appended to atail of one ECC block in the embodiment of FIG. 3, it may be inserted inthe head of each ECC block.

The waste area is corresponding to the header information area allocatedat intervals among recorded data in a DVD-RAM and to the linking lossarea placed every RMD block in a DVD-RW.

The waste area may have a different size other than 2048 bytes inaccordance with the size of the header information area defined in aDVD-RAM or the linking loss area defined in a DVD-RW. If the size of arecording unit, e.g., a sector defined in a disk is smaller than 2048bytes, the size of the waste area can be also smaller than 2048 bytes.

The storage capacity of a DVD-ROM, with a nominal storage capacity of4.7 Gbytes, is correspondingly reduced by the total size of insertedwaste areas. This size reduction makes the substantial storage capacityof a DVD-ROM equal to or less than that of a DVD-RAM and a DVD-RW whichhave the header information areas and the linking loss areas,respectively. Thus, the entire real-time data stored in a DVD-ROM, inwhich the waste areas are allocated at intervals, can be copied onto aDVD-RAM or a DVD-RW.

Described below is a method of seamlessly reproducing the presentread-only recording medium in which a waste area is inserted in everydata unit such as ECC block as explained above.

FIG. 4 is a simplified block diagram of a disk device which areproducing method for a read-only recording medium according to thepresent invention is incorporated therein. The disk device of FIG. 4,which may be a DVD player or a DVD drive, comprises an optical pickup 2detecting signal patterns formed in a DVD-ROM 1; an R/F unit 3converting the detected signal patterns to binary waveforms; a signalprocessor 4 processing the binary waveforms from the R/F unit 3 torestore original digital data; a controller 5 controlling all elementsfor reproduction of the DVD-ROM 1; and a buffer 6 storing temporary dataproduced while reproducing the DVD-ROM 1.

If the waste area is encountered while reproducing the data of theDVD-ROM 1 in the recorded order, the controller 5 removes the invaliddata from the encountered waste area and connects the data reproducedbefore and behind the waste area to seamlessly output reproduced data.This reproducing method is explained below in detail.

FIG. 5 is a flow chart of a preferred embodiment of a method reproducinga read-only recording medium manufactured in accordance with the presentinvention.

When a read-only recording medium, namely, the DVD-ROM 1 containingwaste areas in its stored data is placed in the disk device of FIG. 4(S10), the controller 5 searches the placed DVD-ROM 1 for managementinformation recording area first, then, it reads out the managementinformation, such as navigation data for reproduction control of storeddata, and stores such information in an internal memory (S11).

Afterwards, if a reproduction of the DVD-ROM 1 is requested from a user,the controller 5 moves the pickup 2 to a start point of stored real-timeor other data and conducts data reproducing operation (S13).

While conducting data reproducing operation, the controller 5 checkswhether or not a current reproducing position advances into the wastearea (S14). For example, if the current reproducing position is at asector right after a 32-Kbyte ECC block, composed of 16 sectors, thatsector is regarded as the waste area. Alternatively, other identifierindicative of the waste area may be used for detecting the waste area.

If the waste area is detected by the controller 5, the useless data fromthe detected waste area is removed during the next data processing stepby the controller 5 (S15). For removing the useless data, the controller5 stops storing the reproduced data in the buffer 6 when the waste areais encountered, and resumes the storing operation after the waste areahas ended. Preferably, the end of the waste area is when the next ECCblock begins. Thus, only the recorded data is stored into the buffer 6without the useless data from the waste area.

If the stored data in the buffer 6 is sequentially outputted in theorder the data was stored, the seamless reproduction of the DVD-ROM 1 isachieved (S16). If a reproduction stop is requested from a userafterwards (S17), the controller 6 stops the above seamless reproductionoperation.

Through the above-explained reproducing method, the disk device performsa seamless reproduction of a read-only recording medium whose real oractual data is recorded discontinuously because the waste area has beenperiodically inserted.

If a DVD-RAM or a DVD-RW, in which real data has been recordeddiscontinuously because of the header information area or the linkingloss area, is inserted in the disk device, the controller 5 alsoconducts the invalid data removing operation in the same manner, namely,it stops storing data from the rewritable recording medium when theheader information or the linking loss area is detected, and resumes tostore when the header information or the linking loss area ends whileoutputting the stored data sequentially in storing order. Therefore, itis not needed to distinguish the type of an inserted disk. In otherwords, the disk device of the preferred embodiment may apply the samereproducing algorithm to all disk types, e.g., a read-only disk DVD-ROMand a rewritable disk DVD-RAM or DVD-RW.

Alternative to the above described data removing operation in which theuseless data in the waste area is removed after being reproduced, thewaste area may be skipped immediately by track jump without datareproduction when the waste area is encountered.

Furthermore, instead of allocating the waste areas uselessly, it may bepossible to form in the waste area useful data, e.g., repetitive 8T-long(T is a bit time interval in a recording wave train) pre-pits which canbe used for synchronizing a servo-controlling PLL in later reproduction.

As aforementioned, the substantial storage capacity of the DVD-ROM isreduced below the nominal capacity of 4.7 Gbytes because the waste areasare formed repeatedly every certain data unit, e.g., ECC block. However,the storage shortage due to such capacity reduction will be resolvednaturally if a high-density DVD-ROM whose capacity is above about 15Gbytes is developed in the near future.

The above embodiments for a read-only recording medium were explained inconsideration of an existing recording medium, namely, DVD-RAM andDVD-RW. However, if a next generation of a recording medium isdeveloped, it will be natural that a read-only medium of the nextgeneration have the aforementioned waste area of which size is equal tothat of an intermediary area inserted periodically in actual user datain a counterpart, namely, a rewritable medium of the next generation.

The read-only recording medium and the reproducing method thereof ensurethe reproduction compatibility between a read-only recording medium anda rewritable one and, therefore, make it possible to apply the samereproduction algorithm to both a rewritable and a read-only recordingmedium. As a result, the playability is improved in a disk devicecapable of reproducing both a read-only and a rewritable recordingmedium. In addition, a rewritable recording medium can accommodateentire data stored fully onto a read-only recording medium when a diskcopy is requested.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A read-only recording medium, comprising: a plurality of data unitsrecorded on the read-only recording medium, each data unit connected bya linking data unit having a predetermined size, wherein the linkingdata unit is identified by an identifier.
 2. The read-only recordingmedium of claim 1, wherein the data unit comprises a plurality of firstdata units, and the size of the linking data unit is the same as thefirst data unit.
 3. The read-only recording medium of claim 1, whereinthe size of the linking data unit is the same as a linking area of awritable recording medium, thereby preserving a compatibility with thewritable recording medium.
 4. The read-only recording medium of claim 1,wherein the linking data unit includes a plurality of recorded pits,which have a same length respectively.
 5. The read-only recording mediumof claim 4, wherein the pre-recorded pits are used to control a servooperation.
 6. The read-only recording medium of claim 1, wherein thedata unit and the linking data unit comprise a second data unit.
 7. Theread-only recording medium of claim 1, wherein a total size of the dataunit and the linking data unit is the same as that of a data unit and alinking area in a writable recording medium.
 8. A read-only recordingmedium, comprising: a plurality of data units recorded on the read-onlyrecording medium, each data unit connected by a linking data unit havinga predetermined size, wherein the linking data unit is identified by aposition of the linking data unit inserted in a tail or head of the dataunit.
 9. The read-only recording medium of claim 8, wherein the dataunit comprises a plurality of first data units, and the size of thelinking data unit is the same as the first data unit.
 10. The read-onlyrecording medium of claim 8, wherein the size of the linking data unitis the same as a linking area of a writable recording medium, therebypreserving a compatibility with the writable recording medium.
 11. Theread-only recording medium of claim 8, wherein a total size of the dataunit and the linking data unit is the same as that of a data unit and alinking area in a writable recording medium.
 12. A read-only recordingmedium, comprising: a plurality of data units recorded on the read-onlyrecording medium, each data unit recorded discontinuously by a firstdata area, wherein the each data unit includes real data, and the firstdata area includes an invalid data and an identifier to identify thatthe area is the first data area.
 13. The read-only recording medium ofclaim 12, wherein the data unit comprises a plurality of sub data units,and the size of the first data area is the same as the sub data unit.14. The read-only recording medium of claim 12, wherein the size of thefirst data area is the same as that of non real data area included in adata unit of a writable recording medium, thereby preserving acompatibility with the writable recording medium.
 15. The read-onlyrecording medium of claim 12, wherein the first data area includes aplurality of pre-recorded pits, which have a same length respectively.16. The read-only recording medium of claim 15, wherein the pre-recordedpits are used to control a servo operation.
 17. The read-only recordingmedium of claim 12, wherein a size of the data unit is the same as thatof a data unit including non real data area of a writable recordingmedium.
 18. A method of reproducing data stored in a read-only recordingmedium, comprising: checking whether or not a current position is alinking data area based on an identifier to identify the linking dataarea, the linking data area preceded and followed by a real data area;and removing a useless data in the linking data area and outputtingcontinuously the real data in the real data area before and behind thelinking data area, when the identifier is detected.
 19. A method ofreproducing data stored in a read-only recording medium, comprising:checking whether or not a current position is an invalid data area basedon a position of the invalid data area inserted in a tail or head of areal data area; and removing the invalid data and outputtingcontinuously the real data before and behind the invalid data, when thecurrent position is the tail or head of the real data area.